Safety device for a fall restraint

ABSTRACT

A safety device for a fall restraint includes an anchoring member ( 1 ) to which the fall restraint can be coupled directly or indirectly, and a fastening element for a firm and durable connection to an object ( 13 ). The fastening element are formed by a flexible fastening flap ( 11 ) which is intended and adapted to bring about the firm and durable connection to the object. Extending from the fastening flap ( 11 ) is a fastening net ( 12 ) via which the anchoring member ( 1 ) is connected to the flexible fastening flap ( 11 ).

The present invention relates to a safety device for a fall restraint,comprising anchoring means to which the fall restraint can be coupleddirectly or indirectly, and comprising fastening means for a firm anddurable connection to an object.

Such a device is increasingly finding application, particularly on flatand sloping roofs of houses and buildings as fastening point for a fallrestraint with which a person can hook him/herself during work to theroof or an outer wall of the structure in question in order to preventfalling hazard. This is first and foremost a result of the increasinglystringent regulations in respect of working conditions in which suchwork may be carried out. During work at height on a wall of an objectthe person wears a harness with safety line with which he coupleshim/herself fast to the anchoring member. It is noted here that withinthe scope of the invention the term wall should be understood in a broadsense, so that it should be understood to mean not only an outer wallbut for instance also a roof of an object.

A safety device usually comprises a base from which a fastening eye orother anchoring member extends and which is permanently fixed to theobject. An example of such a safety device is known from the Americanpatent U.S. Pat. No. 5,287,944. The safety device described therein isfastened into the fixed construction of the object by means of a largenumber of screws and plugs. A corresponding number of holes are drilledfor this purpose into the construction of the object at the setposition. In this known safety device the fixing eyelet is formed asintegral part with the base from sufficiently strong plate steel.Another example of a safety device is known from the American patentU.S. Pat. No. 5,687,535, wherein the fastening of a base thereof to theobject takes place by means of one or several bolts which penetrate intothe construction of the object for the purpose of a permanent fixedconnection thereto. A separate fixing eyelet is in turn connected to thebase by means of a nut and bolt connection.

Although these known anchoring devices provide per se a solid andreliable anchor point for a fall restraint, they also have significantdrawbacks. Owing to the relatively rigid connection of the safety deviceto the construction of the object, a possible fall is not absorbedthereby, or hardly so, so that the kinetic energy involved has to beabsorbed wholly in the fall restraint so that it is not exerted on thefalling person. Occasionally it is not possible to avoid the personsuffering injury here. The attachment of the safety device in theseknown cases furthermore requires penetration of the object, which canhave an adverse effect on the integrity of the construction thereof.

The present invention has for its object, among others, to provide asafety device of the type stated in the preamble with which these andother drawbacks are obviated to an at least significant extent.

In order to achieve the stated objective, a safety device of the typestated in the preamble has the feature according to the invention thatthe fastening means comprise a flexible fastening flap from which afastening net extends, and that the anchoring means are connected viathe fastening net to the flexible fastening flap. The safety device withthe anchoring member is thus fastened to the object via the fasteningflap and the fastening net. The fastening flap and the fastening netherein provide a certain shock absorption which can absorb at least apart of the kinetic energy in the case of a possible fall from theobject, whereby personal injury is less serious.

Within the scope of the invention a wide variety of materials can inprinciple be applied for the fastening flap, with solid structure oropenwork net or mesh structure. Particularly if the object is covered atleast locally with a flexible wall-covering material, use canadvantageously be made for the fastening flap of a flexiblewall-covering material, and in particular of a bituminous or plasticroof-covering material. Owing to its inherent flexibility, such awall-covering material provides a high degree of shock-damping in thecase of a fall, which is already broken thereby to a certain extent. Themomentum exerted on the body of a falling person is therefore limited.

The choice of material for the fastening flap in the form of a materialwhich is the same as, similar to or at least significantly compatiblewith the material with which the object is covered at the location,furthermore simplifies the mutual connection between the safety deviceand the object covering. Use is particularly made here of an attachmenttechnique that is also used to arrange the local covering of the object.A further preferred embodiment of the safety device according to theinvention has in this respect the feature that said firm and durableconnection comprises a glue, fastening or welded connection. Not only isthe person who normally arranges the wall covering familiar with thisattachment technique, so that this person must also be deemed capable ofarranging the safety device in reliable manner, such a glue, fasteningor welded connection on the original covering of the object moreoverleaves the integrity of the further construction thereof intact. Inparticular, no drill holes or other holes are therefore necessary in thewall or roof covering, which would otherwise involve the risk ofleakages.

It has been found that with a sufficiently large free surface area ofthe fastening flap a sufficiently strong, reliable and durableconnection can thus be realized. A particular embodiment of the safetydevice according to the invention herein has the feature that thefastening net is attached to the fastening flap or that the fasteningnet is integrated in the fastening flap. Such a connection of thefastening net to the fastening flap can be given a sufficiently strongform to resist a falling standard mass for a sufficiently long time. Inorder to avoid the net per se tearing inward or outward, a furtherparticular embodiment of the safety device according to the inventionhas the feature that the fastening net is reinforced with longitudinalthreads and transverse threads.

The safety device according to the invention will frequently findapplication on roofs on which a suitable roof-covering material from aroll is or will be applied. With a view hereto, a further preferredembodiment of the safety device according to the invention has thefeature that the fastening flap forms part of an optionally unrolledroll of roof-covering material, and more particularly that theroof-covering material comprises a material from a group of plastic andbitumen. In such a case the safety device according to the invention canbe arranged without additional processing steps in that it is realizeden passant simultaneously with laying of the roof-covering. Theincorporation of the fastening net in the complete roof-coveringmoreover has the advantage that mutual connecting strength anddistribution of forces are optimal. A further particular preferredembodiment of the safety device according to the invention has in thisrespect the feature that the fastening net is fixed to an inlay in theroof-covering material and is incorporated simultaneously therewith inthe roof-covering material.

In order to already partially break an unexpected fall in the safetydevice and thus reduce a load on the body of the falling person, afurther particular embodiment of the safety device according to theinvention has the feature that the anchoring means comprise a resilientconstruction.

The invention will now be further elucidated on the basis of a number ofexemplary embodiments and a drawing. In the drawing:

FIG. 1 shows a perspective view of a first exemplary embodiment of asafety device according to the invention;

FIG. 2 shows a cross-section of the device of FIG. 1;

FIG. 2A shows a cross-section of an alternative device of FIG. 1;

FIG. 3 shows a perspective view of a second exemplary embodiment of asafety device according to the invention;

FIG. 4 shows a cross-section of the device of FIG. 3;

FIG. 4A shows a cross-section of an alternative device of FIG. 3;

FIG. 5 shows anchoring means applied in a third embodiment of the safetydevice according to the invention;

FIGS. 6A-B show the anchoring means of FIG. 5 in respectively anon-loaded and a loaded state; and

FIG. 7 shows a perspective view of a third exemplary embodiment of asafety device according to the invention.

The figures are otherwise purely schematic and not drawn to scale. Somedimensions in particular may be exaggerated to a greater or lesserextent for the sake of clarity. Corresponding parts are designated asfar as possible in the figures with the same reference numeral.

A first exemplary embodiment of a safety device for a fall restraintaccording to the invention is shown in FIGS. 1 and 2, respectively inperspective view and in cross-section. The device comprises stronganchoring means in the form of a fixing ring, eyelet or loop 1 memberfastened to an outer end of a fastening net 12. The integrated fasteningnet 12 comprises a metal or plastic mesh or net which is reinforced withlongitudinal and transverse threads in order to distribute forcesexerted thereon over a greater area. Net 12 can have any desired shapeand dimension, for instance round, square, polygonal or, as in thisembodiment, triangular.

A standard fall restraint, for instance a safety line of a fall-arrestharness or safety harness, can be secured to fixing eyelet 1 in usualmanner, for instance by means of a preferably locked karabiner hook orsnap hook, in rapid and reliable manner. The device finds particularapplication for temporarily securing workpeople during operations atheight on an object such as a house, apartment building or industrialinstallation. The device is connected permanently to the object for thispurpose.

The anchoring member 1 is connected via fastening net 12 to fasteningmeans in the form of a flexible fastening flap 11. With its relativelylarge surface area, fastening flap 11 provides an attachment base for adurable fixing of the safety device to an outer wall, roof or other wallof the object. In this embodiment fastening flap 11 forms an integralpart of a roll 10 of flexible roof-covering material. This is moreparticularly a bituminous or plastic roof-covering material intended forfusing or glueing at an increased temperature to a similar roof coveringsuch as applied on many flat and sloping roofs.

The arranging of the safety device on for instance a flat or slopingroof provided with a bituminous roof-covering can be carried outrelatively simply and quickly with hardly any effect on the integrity ofthe original roof-covering. To this end the original roof-covering 13 iscleaned at the location and the roll of roof-covering material 10 withsafety device 1,11 integrated therein is unrolled thereover. Using aconventional burner or hot-air drier the bituminous fastening flap 11 isthen fused at increased temperature with the existing, similarroof-covering to form a cohesive whole. Because there is in principle nopenetration here through the original roof-covering, the watertightnessand integrity of the whole remains ensured. In addition, it is possibleto apply the safety device according to the invention via fastening flap11 directly, i.e. on a bare surface, of an outer wall or roof. Theinvention provides in all cases the advantage that when the necessaryroof-covering is arranged an effective fall restraint is also realizedwithout affecting the integrity of the construction of the object assuch or also interfering therewith.

What is important is a reliable connection between fastening net 12 andfastening flap 11, since this connection, just as that of the covering10,11 to the surface, will be loaded during a fall. With a view hereto,use is made in the stated embodiment of an interweaving or otherattachment of the fastening net 12 with an inlay 15 as is incorporatedfor strengthening purposes over the whole surface of the roof-coveringmaterial. Such an inlay 15 forms a strong yet flexible reinforcement ofroof-covering material 10 which absorbs a lateral pull therein. Becausethis inlay extends over the whole surface of the roof-covering material,the load on the connection between fastening net 12 on the one hand androof-covering material 10,11 on the other is distributed uniformly overthe surface during a possible fall. The device of FIG. 1 is hereinapplied such that such a load occurs substantially in a direction asindicated by the arrow 5 drawn in FIG. 1.

Alternatively, fastening net 12 can also be connected to roof-coveringmaterial 10,11 in reliable manner by glueing the net 12 between twolayers of roof-covering material 10,20 as shown in FIG. 2A. Other thanincorporation in an inlay 15,25 of the roof-covering material, whichmust take place during production, such a fixing between two layers ofroof-covering can also be realized later on-site.

A second embodiment of a device according to the invention is shown inFIGS. 3 and 4. The device here also comprises a fastening flap 11 whichforms an integral part of a roll 10 of roof-covering material. Extendingfrom the device are anchoring means in the form of a fixing ring or loop1, which according to the invention are connected to roof-coveringmaterial 10,11 via a fastening net 12. Other than in the first exemplaryembodiment, the fastening net in this embodiment is connected in diversedirections to the roof-covering material, so that the device can beloaded in different directions as indicated schematically in FIG. 3 witharrows 5. As in the foregoing embodiment, the attachment of fasteningnet 12 can here also take place to an inlay 15 received in roof-coveringmaterial 10,11, see FIG. 4, or by glueing between two layers ofroof-covering material, see FIG. 4A.

FIG. 5 shows a coupling 100 of a fall restraint which can be appliedwith a third exemplary embodiment of a device according to theinvention. This embodiment substantially corresponds with the firstembodiment, except that the anchoring means here comprises a matingcoupling 110 complementary to coupling 100. Coupling 100 and matingcoupling 110 can be snapped together so as to thus bring about arapid-action coupling. Spring-mounted rollers or balls 105 herein snapinto recesses 115 of the mating coupling intended for this purpose.Coupling 100 comprises release means (not further shown) with which snapmembers 105 can be forced manually out of recesses 115 in order to breakthe connection if desired.

Coupling 100 provides the anchoring means 110 with a resilientconstruction which during a fall can absorb a part of the falling forceand thus spare the falling body. FIG. 6A shows in this respect a dampingspring 108 applied herein in released, non-loaded state, while FIG. 6Bshows the same spring 108 in loaded, tensioned state, wherein a body ishanging from an outer end 101. As shown, this end 101 comprises a fixingring, eyelet or loop to which a fall harness can be coupled. It is inaddition possible to embody a safety line with the coupling 100 and thencouple it directly to the safety device.

A third embodiment of a device according to the invention is shown inFIG. 7. A flexible fastening flap 11 here also forms an integral part ofa roll of roof-covering material 10, the same as in the first and secondexemplary embodiments of the device according to the invention whichhave been described above. A fastening net 12 is situated centrally inroll 10 and is constructed in this embodiment solely from reinforcedlongitudinal threads extending over the full length of the roll. Atregular intervals of about 2-3 metres a fixing eyelet or loop 1 isconnected durably to net construction 12 so as to provide at regularintervals anchoring means to which a person can secure him/herself. Roll10 can be unrolled and fixed over an existing roof-covering 13 or beapplied directly as first roof-covering on a sloping or other roof.

The device according to the invention can in principle be applied on anystructural type of roof or outer wall construction, wherein the strengthof the construction is of secondary importance. Examples hereof are roofcoverings or wall claddings of bitumen or plastic which are wholly orpartially adhered, mechanically fixed or ballasted with loose material.The application of the safety device according to the invention complieswith the EN 795 standard known to the skilled person. This standarddescribes the requirements for the testing methods for anchor provisionsintended for personal protection against falls. The two essential pointsfrom the EN 795 standard are:

-   -   a static test wherein a force of 10 kN can be resisted for 3        minutes in the direction in which the force can be applied        during use; and    -   a dynamic test wherein a mass of 100 kg, connected to the anchor        point with a steel cable, is stopped in a free fall of 2500 mm.

Although the invention has been further elucidated above on the basis ofonly a number of exemplary embodiments, it will be apparent that theinvention is by no means limited thereto. On the contrary, manyvariations and embodiments are still possible within the scope of theinvention for a person with ordinary skill in the art. The invention canthus also be applied particularly with an individual fastening flap,i.e. separately of a roll of roof-covering material, wherein thefastening flap is attached individually to the object.

The different embodiments of the safety device for fall restraintaccording to the invention have in common that they are lightweight andcan be mounted rapidly with simple means and tools. Specific to thissafety device is that the force released during a fall is absorbed inelastic manner by the materials from which the device is manufactured.When the occasion demands, a plastic deformation of one or morecomponents of the device will absorb a significant part of the kineticenergy of a fall. The forces are then transmitted to the existingcovering of the roof or the outer wall or to the roof or the outer wallitself.

1. Safety device for a fall restraint, comprising anchoring means towhich the fall restraint can be coupled directly or indirectly, andcomprising fastening means for a firm and durable connection to anobject, characterized in that the fastening means comprise a flexiblefastening flap from which a fastening net extends, and that theanchoring means are connected via the fastening net to the flexiblefastening flap.
 2. Safety device as claimed in claim 1, characterized inthat the fastening net is attached to the fastening flap.
 3. Safetydevice as claimed in claim 1, characterized in that the fastening net isintegrated in the fastening flap.
 4. Safety device as claimed in claim1, characterized in that the fastening net is strengthened withlongitudinal threads and transverse threads.
 5. Safety device as claimedin claim 1, characterized in that the fastening net is manufactured atleast partially from plastic or metal.
 6. Safety device as claimed inclaim 1, characterized in that the fastening flap forms part of anoptionally unrolled roll of roof-covering material.
 7. Safety device asclaimed in claim 6, characterized in that the roof-covering materialcomprises a material from a group of plastic and bitumen.
 8. Safetydevice as claimed in claim 6, characterized in that the fastening net isfixed to an inlay in the roof-covering material and is incorporatedsimultaneously therewith in the roof-covering material.
 9. Safety deviceas claimed in claim 1, characterized in that the anchoring meanscomprise a resilient construction.
 10. Safety device as claimed in claim1, characterized in that the anchoring means comprise a fixing eyelet,ring or loop.
 11. Safety device as claimed in claim 2, characterized inthat the fastening net is strengthened with longitudinal threads andtransverse threads.
 12. Safety device as claimed in claim 3,characterized in that the fastening net is strengthened withlongitudinal threads and transverse threads.
 13. Safety device asclaimed in claim 2, characterized in that the fastening net ismanufactured at least partially from plastic or metal.
 14. Safety deviceas claimed in claim 3, characterized in that the fastening net ismanufactured at least partially from plastic or metal.
 15. Safety deviceas claimed in claim 4, characterized in that the fastening net ismanufactured at least partially from plastic or metal.
 16. Safety deviceas claimed in claim 2, characterized in that the fastening flap formspart of an optionally unrolled roll of roof-covering material. 17.Safety device as claimed in claim 3, characterized in that the fasteningflap forms part of an optionally unrolled roll of roof-coveringmaterial.
 18. Safety device as claimed in claim 4, characterized in thatthe fastening flap forms part of an optionally unrolled roll ofroof-covering material.
 19. Safety device as claimed in claim 5,characterized in that the fastening flap forms part of an optionallyunrolled roll of roof-covering material.
 20. Safety device as claimed inclaim 21, characterized in that the anchoring means comprise a resilientconstruction.